Saturated hydrocarbon averaging

ABSTRACT

A PROCESS FOR AVERAGING SATURATED HYDROCARBON FEED COMPONENTS OF DIFFERENT MOLECULAR WEIGHT TO COMPONENTS OF INTERMEDIATE MOLECULAR WEIGHT RELATIVE TO THE FEED COMPONENTS WHICH COMPRISES CONTACTING THE SATURATED HYDROCARBON FEED COMPONENTS AT A TEMPERATURE BETWEEN ABOUT 400* AND 850*F. IN A REACTION ZONE WITH A CATALYTIC MASS COMPRISING A GROUP VI-B METAL COMPONENT AND A GROUP VIII METAL COMPONENT, AND MAINTAINING THE OLEFIN CONCENTRATION IN THE REACTION ZONE SUFFICIENTLY LOW TO PRODUCE IN THE REACTION ZONE A SATURATED HYDROCARBON PRODUCT CONTAINING SAID COMPONENTS OF INTERMEDIATE MOLECULAR WEIGHT AND CONTAINING LESS THAN 5 MOLE PERCENT OLEFIN PREFERABLY THE CATALYTIC MASS CONTAINS PLATINUM ON ALUMINA (PLATINUM BEING THE GROUP VIII METAL COMPONENT); AND TUNGSTEN OXIDE ON SILICA (TUNGSTEN OXIDE BEING THE GROUP VI-B METAL CONPONENT). LOW OLEFIN CONCENTRAIONS IN THE REACTION ZONE ARE CRUCIAL IN THE PROCESS OF THE PRESENT INVENTION.

"United States Patent 24 Claims ABSTRACT OF THE DISCLOSURE A process foraveraging saturated hydrocarbon feed components of different molecularweight to components of intermediate molecular weight relative to thefeed components which comprises contacting the saturated hydrocarbonfeed components at a temperature between about 400 and 850 F. in areaction zone with a catalytic mass comprising a Group VI-B metalcomponent and a Group VIII metal component, and maintaining the olefinconcentration in the reaction zone sufficiently low to produce in thereaction zone a saturated hydrocarbon product containing said componentsof intermediate molecular weight and containing less than 5 mole percentolefin. Preferably the catalytic mass contains platinum on alu mina(platinum being the Group VIII metal component); and tungsten oxide onsilica (tungsten oxide being the Group VI-B metal component).

Low olefin concentrations in the reaction zone are crucial in theprocess of the present invention.

CROSS-REFERENCES This is a continuation of application Ser. No. 149,068,now abandoned, filed June 1, 1971.

This application is a continuation-in-part of Ser. No. 864,870 nowabandoned, filed Oct. 8, 1969. The disclosure of Ser. No. 864,870 nowabandoned is hereby incorporated by reference into the present patentapplication.

The continuation-impart application of Ser. No. 864,871, filed on orabout June 2, 1971, titled Saturated Hydrocarbon Conversion, is relatedto the present application and is hereby incorporated by reference intothe present application.

BACKGROUND OF THE INVENTION Field of the invention The present inventionrelates to the conversion of sat-- urated hydrocarbon feeds tohydrocarbon products with different molecular weights than those of thefeed hydrocarbons. More particularly, the present invention relates tothe conversion of saturated hydrocarbons of at least two differentmolecular weights to hydrocarbons of inter mediate molecular weight bymeans of an averaging reaction.

The term averaging is used in the specification to mean the conversionof saturated feed components or saturated hydrocarbon molecules ofdifierent molecular Weight to components of intermediate molecularweight relative to the saturated feed components. For example, in anaveraging reaction between butane and hexane, the butane and hexane areconverted to pentane.

Saturated hydrocarbon feed component as used herein includes hydrocarbonmolecules which are completely saturated with hydrogen and/ orhydrocarbon molecules which are partially saturated with hydrogen butcontain at least one alkyl group which is completely saturated withhydrogen. In the case of molecules which are partially unsaturated butcontaining a saturated group,

the term saturated hydrocarbon feed component refers to the saturatedgroup of the molecule. Thus the term saturated hydrocarbon feedcomponent as used herein applied to various molecules such as alkanes(paraflins), branched-chain alkanes, alicyclic hydrocarbons(cycloparaflins) with one or more attached alkyl groups containing atleast two carbon atoms, and unsaturated hydrocarbons with one or moreattached, completely saturated hydrocarbon groups, as, for example, anaromatic hydrocarbon with an attached alkyl group. From the descriptionhereinbelow, it will become apparent that in the instance of unsaturatedhydrocarbons with an attached, completely saturated hydrocarbon group,the conversion process of the present invention operates by way of thecompletely saturated hydrocarbon group. Also, as will be seen to follownaturally from the description of the invention hereinbelow, the termsaturated hydrocarbon component is not used herein to include moleculeswhich have an olefinic constituent, and similarly is not used to includemolecules which have an acetylenic constituent.

Description of the prior art Averaging of saturated hydrocarbons orparaflinic hydrocarbons to form hydrocarbons of intermediate moleculareweight has been carried out, according to prior art, using acidiccatalysts, such as boron fluoride-hydrogen fluoride catalyst. Forexample, US. Pat. 2,216,274 discloses a process for interactingrelatively high molecular weight parafiin hydrocarbons with lowermolecular weight isoparaflin hydrocarbons to form parafiin hydrocarbonsof intermediate molecular weight by contacting the feed hydrocarbonswith a catalytic material consisting essentially of boron fluoride andhydrogen fluoride at temperatures between about -30 and C.

A number of other patents disclose parafiin averaging reactions using acatalyst comprised essentially of boron fluoride and hydrogen fluorideor boron fluoride, hydrogen fluoride and water. These patents includeUS. Pats. 2,296,371, 2,405,993, 2,405,994, 2,405,995, 2,405,996, and2,405,997. The disclosures of the above cited US. patents relating toaveraging reactions are hereby incorated by reference into the presentpatent application, particularly those parts of the disclosures relatingto preferred feed components to be reacted or interacted in an averagingreaction to produce hydrocarbons of intermediate molecular weight.

Numerous processes have also been disclosed using acidic-type catalystsfor the disproportionation of saturated hydrocarbons.

Disproportionation is recognized as a distinct reaction in thehydrocarbon processing industry. For example, in US. Pat. 3,340,322,disproportionation is defined as the conversion of a hydrocarbon intosimilar hydrocarbons of both higher and lower numbers of carbon atomsper molecule. Averaging is often though of as the reverse reaction ofdisproportionation. Sometimes averaging may be considered as the sametype of reaction as disproportionation from the standpoint of reactionmechanism.

Catalysts which have been used in the past for disproportionation ofsaturated hydrocarbons include solid catalysts comprised of AlCl onalumina, boron fluoride with hydrogen fluoride and boron fluoridetogether with a promoter comprised of alkyl fluoride. The use ofaluminum chloride solid catalyst was uneconomic because, among otherreasons, the catalyst was nonregenerable. The use of either boronfluoride with hydrogen fluoride or boron fluoride with an alkyl fluoridewas unattractive because of severe corrosion, sludge formation and otheroperating problems.

US. Pat. 3,445,451 discloses a process for thedehydrogenation-disproportionation of olefins and parafiins, using acombined dehydrogenation and disproportionation catalyst. According toU.S. Pat. 3,445,541, a hydrocarbon feed which is either an acyclicparafiin or acyclic olefin having 3-6 carbon atoms is contacted with thecatalyst at conditions of temperature and pressure to promotedehydrogenation and disproportionation. It is said that the process canbe carried out at temperatures between 800 and 1200 F.; however, thelowest temperature used for processing a parafiin in accordance with anyof the examples of U.S. Pat. 3,445,541 is 980 F. and typically, thetemperature used is between 1040 and 1125 F. In run 22 of U.S. Pat.3,445,451 the temperature used is 900 F. and the feedstock is propylene;that is, the feedstock is an olefin. Olefin feedstocks as well assubstantial formation of olefins in the reaction zone are antithetic tothe process of the present invention, as will be seen in more detailfrom the description of the present invention below.

Also, the feed which is converted in the examples of U.S. Pat. 3,445,541consists of only one feed component in each of the experimental runs;that is, the feed used in the examples was either propane or propylene.Averaging reactions are not described or disclosed in U.S. Pat. 3,445,-541.

SUMMARY OF THE INVENTION According to the present invention a process isprovided for averaging saturated hydrocarbon feed components ofdifferent molecular weight to components of intermediate molecularweight relative to the feed components which comprises contacting thesaturated hydrocarbon feed components at a temperature between about 400and 850 F. in a reaction zone with a catalytic mass comprising a GroupVI-B metal component and a Group VIII metal component, and maintainingthe olefin concentration in the reaction zone sufiiciently low toproduce in the reaction zone a saturated hydrocarbon product containingsaid components of intermediate molecular weight and containing lessthan 5 mole percent olefin.

I have found that it is preferred to carry out the averaging reaction ofthe present invention below 800 F.; for example between 400 and 800 F.Also, I have found that a particularly preferred catalyst compositionfor use in the process of the present invention comprises platinum onalumina as the alkane dehydrogenation component and tungsten oxide onsilica as the olefin averaging component.

The process of the present invention is based on a number of findings.Among the most important findings is that the olefins in the reactionzone must be maintained low in order to avoid substantially inhibitingthe averaging reaction for the formation of saturated hydrocarbonproducts from saturated hydrocarbon feed components. It is specificallypreferred in the process of the present invention to maintain the olefinconcentration in the reaction zone sufficiently low to produce asaturated hydrocarbon product containing less than 5 mole percentolefins. I have found that it is even more preferable to maintain olefinconcentrations sufiiciently low so that the reaction zone product willcontain less than 3 mole percent olefins. It, of course, naturallyfollows that in order to produce a product containing less than 5 molepercent olefins the olefin level in the reaction zone must be maintainedbelow 5 mole percent. For my invention I specifically require that theolefin concentration in the reaction zone be maintained below 5 molepercent of the hydrocarbons. It is crucial for my invention to maintainthe olefin concentration in the reaction zone quite low. The olefinconcentration in the product is referred to rather than the olefinconcentration in the reaction zone because measurement of the reactionzone product is perhaps the most natural way to measure the olefinconcentration in the reaction zone.

Another important finding upon which the present invention is based isthat the temperature must be kept relatively low in order to attain anattractive process for the averaging of saturated hydrocarbon feedcomponents.

The relatively low temperatures employed in the process of the presentinvention are not only critical in that they operate to achieve lowolefin concentrations in the reaction zone, but also the lowertemperature has been .found to reduce the fouling rate of my catalystand to improve the selectivity toward production of saturatedhydrocarbon feed components intermediate to the feed saturatedhydrocarbon components and avoid production of light ends.

Specific temperatures employed in the process of the present inventioninclude temperatures between 400 and 850 F., preferably the temperatureis below 800 F., for example 400 to 799 F.; and I have found that it iseven more advantageous from the standpoint of long catalyst life andhigh selectivity to intermediate products to use a temperature of 775 F.or lower, for example 400 to 775 F.

A particularly preferred embodiment of the present invention is based onmy further finding that a catalyst mass comprising platinum on aluminaand tungsten oxide on silica gives unexpectedly high yields ofintermediate products under the process conditions of the presentinvention indicated above.

In general, the catalyst mass using the process of the present inventionmust contain a Group VIII metal component and a Group VI-B metalcomponent.

The term metal component is used herein to include a metal from thespecified group in the elemental form or in compound form. Preferably,the Group VIII metal component is a platinum group metal or compoundthereof. The platinum group includes platinum, palladium, iridium,rhodium, osmium, and ruthenium. The Group VI-B component is tungsten ormolybdenum or compounds thereof, most desirably as the oxide.

Suitable pressures for use in the averaging reaction zone are betweenabout atmospheric and 2500 p.s.i.a., and more usually between about and1500 p.s.i.a.

Although the process can be applied to the various saturatedhydrocarbons as defined hereinabove, the process is preferably carriedout using alkanes as the saturated hydrocarbon feed. The term alkanes isused herein to mean open chain hydrocarbons from the group of aliphatichydrocarbons of the series C H- excluding methane. Hence according to apreferred embodiment of the present invention, the saturated hydrocarbonfeed comprises two different molecular weight alkanes, or alkanes in atleast two dilferent molecular weight ranges. According to a particularlypreferred embodiment of the present invention, the saturated hydrocarbonfeed which is averaged comprises normally gaseous alkanes and normallyliquid alkanes. Preferably the normally gaseous alkanes consistessentially of propane or normal butane, or isobutane, or mixturesthereof; and the normally liquid alkanes consist essentially of normalor branched-chain pentanes, or hexanes, or heptanes, or octanes orhigher molecular weight alkanes up to about C or mixtures thereof.

In some instances, it is desirable to apply the process of the presentinvention to two or more liquid alkanes; examples of such feed mixturesare C C and/or 0; alkanes, together with naphtha boiling-rangehydrocarbons or kerosene boiling-range hydrocarbons.

The process of the present invention is particudarly.

advantageously applid to interacting or averaging light alkanes such asC s, C s, or C s with heavier hydrocarbons such as naphthas or keroseneboiling-range hydrocarbons. For example, interacting such light alkaneswith hydrocarbon fractions boiling mainly near the higher end of thegasoline boiling range would give, by the present process, a productlargely in the gasoline boiling range and having an increased octanenumber where the initial gasoline fraction has a low octane. Inaccordance with a particularly preferred embodiment of the presentinvention, C alkanes are interacted with a paraffin-rich naphtha,preferably a naphtha rich in C to C hydrocarbons. A Kuwait naphtha whichis rich in parafiin containing for example, 65-80 percent paraflins, -30percent naphthenes, and about 5 percent aromatics, is a particularlypreferred paraffin-rich naphtha feedstock for the process of'thepresent-invention. A raffinate from aromatic-extraction, for examplefrom the extractionof xylenes from a hydrocarbon mixture, is also aparticularly preferred paraffin-rich feedstock for the process of thepresent invention. Another desirable feed is a mixture of C to Chydrocarbons and a wax or waxy fraction, for example of about carbonatoms, which by the present averaging process can be converted toacceptable jet fuel.

I have found that a catalyst mass which comprises a physical mixture ofcatalyst particles containing a Group VIII metal component and catalystparticles containing a Group VI-B metal component is effective foraveraging saturated hydrocarbon components in accordance with theprocess of the present invention, The two types of catalyst particleswhich can be used for the catalyst mass, in that instance wherethecatalyst massis aphysical mixture, should be in close proximity tooneanother. By close proximity is meant a distance of less than a fewinches and preferably of the order of aninch or less. More intimatemixtures can be obtained by mixing or. grinding together fine powders ofthe two kinds of catalyst particles. In certain instances rather thanmakingup the catalyst mass by physical admixtureof two types of.catalyst particles, it is more convenient and more desirable to use onlyone type of catalyst particles comprising .both the Group VIII metalcomponent and Group VI-Bacomponent.

The catalytic mass used in the averaging reaction zone preferablycomprises a platinum group metal or metal compound on a refractorysupport and a Group VI-B,

metal or metal compound on a refractory support. For example, especiallysuitable for use in the present process are catalytic masses formed ofmixtures of platinum on alumina particles and tungsten-oxide-on-silicaparticles.

Other Group VI-B metals include molybdenum and chromium while otherGroup VIII metals include palladium, osmium, rhodium, rutheniumandiridium. These Group VI-B metal component and Group VIII-metal.

component. For example, there may bepresent Sn or,R e,

Particularly desirable is the combination of W0 onSiO together with Pt,Li on A1 0 The particles making up the catalytic mass can be prepared inany suitable manner for obtaining catalytically active amounts of themetal components such as in the form of a dispersion or deposit on asuitable carrier. Thus, platinum or other Group VIII metal can beassociated with a porous inorganic oxide carrier by impregnation,cogellatio'n, coprecipitation or ion exchange and converted to metalform by reduction. For the Group VI-B component, there can be usedsupported'tungsten oxide prepared by impregnation, cogellation, orcoprecipitation as from a water soluble tungstate with subsequentcalcination. a

The porous solid carrier or support employed in the preparation of thecatalyst mass canbe, for example, silica, alumina, charcoal, or carbon,but is preferably a high surface area inoragnic oxide carrier, i.e.,refractory oxide. a

Although the process of the present inventionv can use a catalyticcomponent which has dehydrogenation activity it should be noted that thereaction conditions employed in the process of the presentinventiomparticularly the. preferred low temperature .for carrying outthe overall averaging reaction, are not favorable conditions for the netdehydrogenation of a substantial fraction of feed alkanes, but ratherare such as to minimize net dehydrogenation. Keeping net dehydrogenationlow (i.e., net olefin production low) as determined by the reaction zoneefiluent-is crucial in the process of the present invention. Moreparticularly, it is crucial in the process of the present invention tooperate under conditions which will keep the olefin concentration low inthe reaction zone.

It is usually preferred in the process of the present invention that theportion of the catalytic mass containing the Group VIII metal componenthas a relatively low acidity, that is, low H+ donating value in the caseof Bronsted acids, or low capacity to form strong coordinate covalentbonds to Lewis bases in the case of Lewis acids. This may beaccomplished by the addition of a small amount of alkali metal oxide(such as lithium oxide) or alkaline earth oxide to the Group VIII metalcontaining portion or component of the catalytic mass. It is usuallypreferred in the process of the present invention that essentially theentire catalytic mass have a relatively low acidity.

Examples of catalyst supports and catalysts of low acidity include A1 0with an alkali metal or alkali metal oxide of lithium, sodium, orpotassium to poison the acidic activity of the alumina catalyst support;essentially pure A1 0 essentially pure SiO or either the pure A1 0 orpure Si0 refractory supports with a metal deposited thereon, such as ametal selected from Groups VI-B or VIII'of 'the Periodic Table. Examplesof catalysts of high or moderate acidity include AlCl on A1 0 fluoridedA1 0 hydrogen mordenite; HF or an alkyl fluoride together with BF thehydrogen, rare earth or decationized forms of Y-zeolite; and SiOtogether with A1 0 EXAMPLE 1 The following conditions were employed in alaboratory run for the averaging of saturated hydrocarbons:

Feed: Normal butane and normal octane Volume of catalyst in reactor: 9cubic centimeters (cc.) Catalyst: 2 cc. of 0.5 wt. percent Pt, 0.5 wt.percent Re, and 0.5 wt. percent Li on A1 0 and 7 cc. of 8.0 wt. percentW0 on SiO for a total of 9 cc. of catalyst. Both types of catalystparticles were 28 to 60 Tylermesh size, and the catalyst particles wereuniformly mixed together. Operating conditions:

Temperature: 800' F. Pressure: 900 p.s.i.g.

Feed-rate: 3 cc./hour of normal butane 6 cc./hour of normal octane Theproduct as shown below in Table I was obtained after operating for onehour in accordance with the above operating conditions.

fins was present in the total product before hydrogenating).

- The above results illustrate the eifectiveness of the process of thepresent invention for averaging saturated hydrocarbons to obtainintermediate molecular weight hydrocarbons. A yield of 28.91 weightpercent intermediate (C C and C7) hydrocarbons was obtained innonrecycle operation at a temperature of 800 F., thus supporting theeifectiveness of the operation of the present invention at relativelylow temperatures compared to, for example, those used in the process ofU.S. Pat. 3,445,541.

EXAMPLE 2 Table II below compares results for four runs at varyingn-octane to n-butane feed ratios. The operating conditions were the sameas those set out in Example 1, except for the ratio of n-C to n-C TABLEII Intermediate Feed Products roduct (v01. percent) (wt. percent) (wt.percent) Total of C3 C4 C5 Ca C C C5 and C The results shown above inTable II illustrate that the n-C and n-C feed constituents interact toform intermediate products, i.e., C C and C s. If the n-C n-C feed wassimply disproportionated, a yield of about 24 weight percent C C Cintermediate product would be obtained. When 100% n-C is fed (and thusdisproportionated) a yield of 24 weight percent C C C is obtained. When100% n-C is fed (and thus disproportionated) a yield of 24 weightpercentn-C C C is obtained. But when a mixture of n-C and H-Cg is fed, a yieldof about 29 to 31 wt. percent C C C is obtained. The increase of about25 weight percent C C C when the mixture of n-C and n-C is fedillustrates that the n-C and n-C are interacting or undergoing averagingreaction in accordance with the process of the present invention, ratherthan simply being disproportionated.

EXAMPLE 3 In this example, normal butane is averaged with a raffinatecomposed primarily of C and C parafiins.

The C hydrocarbons can be obtained from various sources such aspetroleum distillates or from excess butanes from hydrocracking orcatalytic reforming or other refinery process operations. The rafiinateused in this example was a raflinate left after solvent extraction ofaromatics from a portion of the eflluent from a catalytic reformingprocess.

The conditions used to carry out the averaging reactions included atemperature of about 800 F., a pressure of about 900 p.s.i.g., a feedrate of about 9 cubic centimeters per hour of 1 part by volume rafiinatewith 2 parts by volume normal butane, a liquid hourly space velocity of1.0 and catalyst consisting of 2 parts by volume .of a 0.5 weightpercent platinum plus 0.5 weight percent lithium on alumina togetherwith 7 parts by volume of 8.0 percent tungsten oxide (calculated astungsten) on silica.

The feed composition and the product or result of the averaging reactionare shown in Table III below. Of the 63 percent butane in the feed, over39 percent was con verted to products of different carbon number. The Cliquid content increased 28 percent, from 37 percent in the feed to 65percent in the product. Essentially all of this net increase in liquidcontent was in the C to (3-, range intermediate in molecular weightbetween the light and heavy feed components. Thus averaging was the mainresult of the process. The 9 percent increase in 0 is not due toaveraging, but to a relative small amount of disproportionationaccompanying the averaging. Most of the 11 percent of C to C parafiinsproduce was propane, which 8 can advantageously be used in liquifiedpetroleum gas (LPG).

TABLE III Feed, Product, Wt. wt. Components percent percent Net change+1. 71 A(C1Cs) =+11.26% it s: 10:24 AC4=-39.18%

+2. 49 +8.30 i2: A o.-o1)=+2s.2o% +4.42 +3. 65

EXAMPLE 4 In this example, a parafiinic-rich rafiiniate comprisingmostly C and C hydrocarbons was averaged with a paraflin in the range Cto C specifically n-hexadecane (C The reaction conditions weresubstantially the same as those used in the previous example, exceptthat the temperature was 700 F. instead of 800 -F. The feed to thereaction zone was 50 volume percent of C -C rich raffinate containing82.1% parafiins, 12.3% naphthenes, and 5.7% alkyl beneznes, and 50volume percent n-hexadecane.

With only one pass through the reactor, over 25 weight percent of thefeed was converted to material boiling between the rafiinate andn-hexadecane, specifically between about 350 F. and 550 F. Thus arelatively high yield of saturated hydrocarbons (jet fuel hydrocarbons)was ob tained with only one pass operation. It is preferable to recyclemost or all of the unconverted hydrocarbons boiling above 550 F. foraveraging with raffinite to convert the unconverted 550 F.+ hydrocarbonsto jet fuel and lighter hydrocarbons.

In the one pass operation, substantial amounts of gasoline boiling rangehydrocarbons are produced in addition to the jet fuel boiling rangehydrocarbons. The gasoline boiling range hydrocarbons can be Withdrawnfor use as gasoline blending stock or for further processing to increasethe octane rating of the gasoline boiling range bydrocarbons, or thegasoline boiling range hydrocarbons can be recycled for furtheraveraging.

A small amount of very light hydrocarbons are produced in any case, andthese very light hydrocarbons can be used as LPG.

Although various embodiments of the invention have been described, it isto be understood they are meant to be illustrative only and notlimiting. Certain features may be changed without departing from thespirit or essence of the invention. The present invention has broadapplication to the averaging of saturated hydrocarbon decomponents,particularly to the averaging of alkanes. Accordingly, the invention isnot to be construed as limited to the specific embodiments or examplesdiscussed, but only as defined in the appended claims or substantialequivalents thereto.

What is claimed is:

1. A process for averaging saturated hydrocarbon feed components ofdifierent molecular Weight to components of intermediate molecularweight relative to the feed components which comprises contacting thesaturated hydrocarbon feed components at a temperature between about 400and 850 F. in a reaction zone with a catalytic mass comprising a GroupVI-B metal component and a Group VIII metal component, and maintainingthe olefin concentration in the reaction zone sufiiciently low toproduce in the reaction zone a saturated hydrocarbon product containingsaid components of intermediate molecular weight and containing lessthan 5 mole percent olefin.

2. A process in accordance with claim 1 wherein the catalytic masscomprises a physical mixture of (a) catalyst particles containing aGroup VI-B metal component and (b) catalyst particles containing a GroupVIII metal component.

3. A process in accordance with claim 1 wherein the saturatedhydrocarbons are contacted with said catalytic mass in a reaction zoneat a temperature below 800 F.

4. A process in accordance with claim 1 wherein the temperature withinthe reaction zone is maintained at 775 or lower.

5. A process in accordance with claim 1 wherein the olefin concentrationin the reaction zone is maintained sufficiently low to produce asaturaetd hydrocarbon product containing less than 3 mole percentolefin.

6. A process in accordance with claim 5 wherein the temperature in thereaction zone is maintained between 400 and 799 F.

7. A process in accordance with claim 1 wherein the catalytic masscomprises a platinum group component on a refractory support and a GroupVI-B metal component on a refractory support.

8. A process in accordane with claim 1 wherein the catalytic masscomprises platinum on alumina and tungsten oxide on silica.

9. A process in accordane with claim 1 wherein essentially the entirecatalytic mass has a low acidity.

10. A process in accordance with claim 2 wherein (a) the catalystparticles in containing the Group VIB metal component comprise tungstenoxide on silica and (b) the catalyst particles containing the Group VIIImetal component comprise platinum on alumina.

11. A process in accordance with claim 2 wherein essentially the entirecatalytic mass has a low acidity.

12. A process in accordance with claim 1 wherein the saturatedhydrocarbons consist essentially of alkanes.

13. A process in accordance with claim 1 wherein the saturatedhydrocarbons consist of light hydrocarbons such as propane, or normalbutane, or isobutane or mixtures of any of those hydrocarbons; andheavier alkanes such as normal or branched-chainz pentanes, or hexanes,or heptanes, or octanes, or higher molecular weight alkanes up to aboutC or mixtures of any of those normally liquid hydrocarbons.

14. A process for averaging feed alkanes of difierent molecular weight(and of molecular weight higher than propane) to alkanes of intermediateweight relative to the feed alkanes which comprises contacting the feedalkanes at a temperature between 400 and 850 F. in a reaction zone witha catalytic mass comprising a Group VI-B metal component and a GroupVIII metal component, and maintaining the olefin concentration in thereaction zone sufliciently low to produce in the reaction 10 zone analkane product containing said alkanes of intermediate molecular weightand containing less than 5 mole percent olefin.

15. A process in accordance with claim 14 wherein the temperature in thereaction zone is maintained between 400 and 799 F.

16. A process in accordance with claim 14 wherein the temperature ismaintained at 775 F. or lower.

17. A process in accordance with claim 14 wherein the temperature ismaintained between 400 and 799 F. and wherein the olefin concentrationin the reaction zone is maintained sufiiciently low to produce in thereaction zone an alkane product containing less than 3 mole percentolefin.

18. A process in accordance with claim 14 when the feed alkanes comprisenormal butane and normal octane.

19. A process in accordance with claim 14 wherein the feed alkanes tothe reaction zone contain no more than about 5 mole percent olefins.

20. A process in accordance with claim 14 wherein the temperature in thereaction zone is maintained between about 650 F. and 850 F.

21. A process in accordance with claim 14 wherein the catalytic masscomprises platinum on alumina and tungsten oxide on silica.

22. A process in accordance with claim 14 wherein the catalytic masscomprises platinum and lithium on alumina and tungsten oxide on silica.

23. A process in accordance with claim 14 wherein the catalytic masscomprises a physical mixture of (a) catalyst particles containing aGroup VI-B component and (b) catalyst particles containing a Group VIIImetal component.

24. A process in accordance with claim 23 wherein (a) the catalystparticles containing the Group VI-B metal component comprise tungstenoxide on silica and (b) the catalyst particles containing the Group VIIImetal component comprise platinum on alumina.

References Cited UNITED STATES PATENTS 3,445,541 5/1969 Heckelsberg eta1. 260-683 D 3,261,879 7/1966 Banks 260-683 D 3,446,868 5/1969 Box260-676 3,484,499 12/1969 Lester 260673 3,668,268 6/ 1972 Mulaskey260676 DELBERT E. GANTZ, Primary Examiner I M. NELSON, AssistantExaminer US. Cl. X.R. 260683 D Po-ww UNITED STATfiPA-II OFFICECERTIFICATE OF CORREQIION Patent No. 3 ,793 ,2531 Dated FebruaryInventor-(s) Thomas R Hughes It is certified that error appears in theabove-identified patent and that said 'Letters Patent are herebycorrected as shown below:

2201. 2, line l, "applied" should read --applies-- .1

Col. 2, lines 2 +-25, "moleculare" should read --molecula'r--.

Col. 2, lines +2-H3, "incorated" should read --incorporated-.

Col. 4, line 62, "particudarly" should read --particularly--.

Col.- 5, line 66, "inoragnic" should read --inorganic--.

Col. 7, line 7i, "produce" should read -produced--. Col. 8 Table III,Col. l, "+9 ,30%" should read --+9. 30

Col. 8, line 29, "beneznes" should read --benzenes--.

Col. 9, Claim '4, "775" should read --775F.--. Col. 9, Claim 5,"saturaeted" should read --sa'turated--.

.Col. 9, Claim 8', "accordane" should read --accordance-. Col. 9, Claim9, "accordane" should read --accordance--. im 10, "particles incontaining" should read --particles containing--.

Signed and sealed this 1st day of October 1974.

(SEAL) Attest:

McCOY M. GIBSON JR. c. "IARSHALL DANN Attesting Officer Commissioner ofPatents L p J

